1. Technical Field
This technology pertains generally to sonification systems and methods, and more particularly to sonification systems and methods for auditory display of physiological parameters during patient monitoring.
2. Background Discussion
Clinical settings requiring simultaneous monitoring of time-varying fluctuations in multiple physiologic parameters present a challenge for clinical staff who must make therapeutic decisions based on changes in these parameters. Although most monitoring devices sound auditory alarms when values of physiologic parameters cross preset thresholds, such alarms are often limited in utility, in large part because the number of false alarms is so high that the alarms are ignored. Often, they also continue sounding when parameter values have returned to a normal range, thus requiring staff to interrupt current tasks in order to turn the alarm off. Importantly, alarms associated with different physiologic parameters are rarely integrated into a coherent information stream. These various considerations have led to a general dissatisfaction with the state of auditory display in clinical settings and calls for improvement of medical information displays.
Part of the challenge in altering the soundscape of clinical settings is to make the auditory information more informative. One attempt to do so is represented by the IEC 60601-1-8 melodic alarm standard in which different monitored parameters are associated with specific melodies. Despite the appeal of such an idea, testing of the ability to learn and discriminate what alarm conditions the different melodies signify has shown this standard to be unusable, prompting some to call for a revision of the standard.
Although it is important to maintain monitored physiologic parameters within acceptable ranges, in many clinical settings, the need for particular attention to this issue in neonatal intensive care patients is becoming increasingly apparent. For example, oxygen saturation targeting has become an important strategy to decrease morbidity from over- or under-oxygenation. Excessively high oxygen saturation is associated with retinopathy of prematurity, while low levels of saturation are concerning for potential risks of inadequate oxygen delivery to developing tissues. While maintaining oxygen saturation within target goals is desirable, it remains challenging to achieve in the clinical setting. It has been demonstrated that actual oxygen saturation levels often exceed the desired ranges, with more of a predilection for excessive levels.
Delivery room stabilization of extremely preterm infants presents another challenge. Providers are faced with new recommendations to achieve a changing target of oxygen saturation while simultaneously performing other stabilizing interventions. Current monitoring strategies focus on visual display of data and alarms when thresholds are exceeded. The noise of alarms themselves may have destabilizing effects on the fragile stability of vulnerable sick neonates, while giving little opportunity to make adjustments to prevent alarm conditions.